<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>index1</title>
	</head>
	<script language="JavaScript">
		var s=1;
		while(n>0){
			s*=n;
			n--;
		}
		return s;
	}
	alert(fun(5));
	</script>
	<body>
		js
	</body>
</html>
